We prove a Nekhoroshev type theorem for the derivative wave equation
$ \begin{equation*} u_{tt} = u_{xx}-mu-(D^{\alpha}u)^3, \quad \ D = \sqrt{-\partial_{xx}+m} \end{equation*} $
under Dirichlet boundary conditions and $ 0\leq \alpha\leq 1 $. More precisely, we prove the sub-exponential long time stability result in a smooth function space and the exponential long time stability result in a modified Sobolev space around the origin for the above equation, where using Birkhoff normal form technique for infinite dimensional Hamiltonian systems and the so-called $ {tame} $ property of the non-linearity. This result is inspired by Bambusi-Grébert (2006, Duke) and a recent work by Feola-Massetti (arXiv: 2207.09986v1).
| Citation: |
| [1] |
D. Bambusi, Birkhoff normal form for some nonlinear PDEs, Comm. Math. Phy., 234 (2003), 253-285.
doi: 10.1007/s00220-002-0774-4.
|
| [2] |
D. Bambusi, M. Berti and E. Magistrelli, Degenerate KAM theory for partial differential equations, J. Differential Equations, 250 (2011), 3379-3397.
doi: 10.1016/j.jde.2010.11.002.
|
| [3] |
D. Bambusi and B. Grébert, Birkhoff normal form for partial differential equations with tame modulus, Duke Math. J., 135 (2006), 507-567.
doi: 10.1215/S0012-7094-06-13534-2.
|
| [4] |
D. Bambusi and B. Langella, A $C^{\infty}$ Nekhoroshev theorem, Math. Eng., 3 (2020), 1-17.
doi: 10.3934/mine.2021019.
|
| [5] |
S. Barbieri, J.-P. Marco and J. E. Massetti, Analytic Smoothing and Nekhoroshev Estimates for Hölder Steep Hamiltonians, Comm. Math. Phys., 396 (2022), 349-381.
doi: 10.1007/s00220-022-04464-0.
|
| [6] |
J. Bernier, E. Faou and B. Grébert, Rational normal forms and stability of small solutions to nonlinear Schrödinger equation, Ann. PDE., 6 (2020), Paper No. 14, 65 pp.
doi: 10.1007/s40818-020-00089-5.
|
| [7] |
J. Bernier, E. Faou and B. Grébert, Long time behavior of the solutions of NLW on the d-dimensional torus, Forum Math. Sigma., 8 (2020), Paper No. e12, 26 pp.
doi: 10.1017/fms.2020.8.
|
| [8] |
J. Bernier and B. Grébert, Long time dynamics for generalized Korteweg-de Vries and Benjamin-Ono equations, Arch. Ration. Mech. Anal., 241 (2021), 1139-1241.
doi: 10.1007/s00205-021-01666-z.
|
| [9] |
M. Berti, L. Biasco and M. Procesi, KAM theory for the Hamiltonian derivative wave equation, Ann. Sci. Éc. Norm. Supér., 46 (2013), 301-373.
doi: 10.24033/asens.2190.
|
| [10] |
M. Berti, L. Biasco and M. Procesi, KAM for reversible derivative wave equations, Arch. Ration. Mech. Anal., 212 (2014), 905-955.
doi: 10.1007/s00205-014-0726-0.
|
| [11] |
M. Berti and P. Bolle, Cantor families of periodic solutions for wave equations via a variational principle, Adv. Math., 217 (2008), 1671-1727.
doi: 10.1016/j.aim.2007.11.004.
|
| [12] |
M. Berti and J.-M. Delort, Almost Global Solutions of Capillary-Gravity Water Waves Equations on the Circle, Lecture Notes of the Unione Matematica Italiana, Springer, Cham, 2018.
doi: 10.1007/978-3-319-99486-4.
|
| [13] |
L. Biasco, J. E. Massetti and M. Procesi, An abstract Birkhoff normal form theorem and exponential type stability of the 1d NLS, Comm. Math. Phys., 375 (2020), 2089-2153.
doi: 10.1007/s00220-019-03618-x.
|
| [14] |
L. Biasco, J. E. Massetti and M. Procesi, Almost periodic invariant tori for the NLS on the circle, Ann. Inst. H. Poincaré Anal. Non Linéaire, 38 (2021), 711-758.
doi: 10.1016/j.anihpc.2020.09.003.
|
| [15] |
J. Bourgain, Remark on stability and diffusion in high-dimensional Hamiltonian systems and partial differential equations, Ergo. Th. Dynam. Sys., 24 (2004), 1331-1357.
doi: 10.1017/S0143385703000750.
|
| [16] |
J. Bourgain, On invariant tori of full dimension for 1D periodic NLS, J. Funct. Anal., 229 (2005), 62-94.
doi: 10.1016/j.jfa.2004.10.019.
|
| [17] |
Q. Chen, H. Cong, L. Meng and X. Wu, Long time stability result for 1-dimensional nonlinear Schrödinger equation, J. Differential Equations, 315 (2022), 90-121.
doi: 10.1016/j.jde.2022.01.032.
|
| [18] |
L. Chierchia and J. You, KAM tori for 1D nonlinear wave equations with periodic boundary conditions, Comm. Math. Phys., 211 (2000), 497-525.
doi: 10.1007/s002200050824.
|
| [19] |
H. Cong, C. Liu and P. Wang, A Nekhoroshev type theorem for the nonlinear wave equation, J. Differential Equations, 269 (2020), 3853-3889.
doi: 10.1016/j.jde.2020.03.015.
|
| [20] |
H. Cong, L. Mi and Y. Shi, Super-exponential stability estimate for the nonlinear Schrödinger equation, J. Funct. Anal., 283 (2022), No. 109682.
doi: 10.1016/j.jfa.2022.109682.
|
| [21] |
H. Cong, L. Mi and P. Wang, A Nekhoroshev type theorem for the derivative nonlinear Schrödinger equation, J. Differential Equations, 268 (2020), 5207-5256.
doi: 10.1016/j.jde.2019.11.005.
|
| [22] |
H. Cong and X. Yuan, The existence of full dimensional invariant tori for 1-dimensional nonlinear wave equation, Ann. Inst. H. Poincaré C Anal. Non Linéaire, 38 (2021), 759-786.
doi: 10.1016/j.anihpc.2020.09.006.
|
| [23] |
E. Faou and B. Grébert, A Nekhoroshev-type theorem for the nonlinear Schrödinger equation on the torus, Anal. PDE., 6 (2013), 1243-1262.
doi: 10.2140/apde.2013.6.1243.
|
| [24] |
R. Feola, F. Giuliani and S. Pasquali, On the integrability of Degasperis-Procesi equation: Control of the Sobolev norms and Birkhoff resonances, J. Differential Equations, 266 (2019), 3390-3437.
doi: 10.1016/j.jde.2018.09.003.
|
| [25] |
R. Feola, B. Grébert and F. Iandoli, Long time solutions for quasi-linear Hamiltonian perturbations of Schrödinger and Klein-Gordon equations on tori, preprint, 2020, arXiv: 2009.07553.
|
| [26] |
R. Feola and F. Iandoli, Long time existence for fully nonlinear NLS with small Cauchy data on the circle, Ann. Sc. Norm. Super. Pisa Cl. Sci., 5 (2021), 109-182.
|
| [27] |
R. Feola and J. Massetti, Sub-exponential stability for the Beam equation, preprint, 2022, arXiv: 2207.09986.
|
| [28] |
G. Gentile and M. Procesi, Periodic solutions for a class of nonlinear partial differential equations in higher dimension, Comm. Math. Phys., 289 (2009), 863-906.
doi: 10.1007/s00220-009-0817-1.
|
| [29] |
M. Guardia, Z. Hani, E. Haus, A. Maspero and M. Procesi, Strong nonlinear instability and growth of Sobolev norms near quasiperiodic finite gap tori for the 2d cubic NLS equation, J. Eur. Math. Soc., (2022).
doi: 10.4171/jems/1200.
|
| [30] |
P. Lochak, Hamiltonian perturbation theory: Periodic orbits, resonances and intermittency, Nonlinearity, 6 (1993), 885-904.
doi: 10.1088/0951-7715/6/6/003.
|
| [31] |
J.-P. Marco and D. Sauzin, Stability and instability for gevrey quasi-convex near-integrable hamiltonian systems, Publ. Math. Inst. Hautes Tudes Sci., 96 (2003), 199-275.
doi: 10.1007/s10240-003-0011-5.
|
| [32] |
A. Maspero and M. Procesi, Long time stability of small finite gap solutions of the cubic nonlinear Schrödinger equation on $\mathbb{T}^2$, J. Differential Equations, 265 (2018), 3212-3309.
doi: 10.1016/j.jde.2018.05.005.
|
| [33] |
C. E. Wayne, Periodic and quasi-periodic solutions of nonlinear wave equations via KAM theory, Comm. Math. Phys., 127 (1990), 479-528.
doi: 10.1007/BF02104499.
|
| [34] |
X. Yuan, Quasi-periodic solutions of completely resonant nonlinear wave equations, J. Differential Equations, 230 (2006), 213-274.
doi: 10.1016/j.jde.2005.12.012.
|